This application claims priority from German Patent Application No. 100 63 459.1, filed Dec. 19, 2000.
The invention relates to the structure of a lightweight door for motor vehicles, i.e. a body-in-white door which, after the painting process, will be completed with further installed components such as window lifts, interior door panels etc.
The design of doors for motor vehicles is determined by various requirements. These include e.g. static rigidity requirements, dynamic rigidity requirements as well as requirements concerning installation space and the arrangement of installed components. Static rigidity requirements include for example requirements relating to bending and torsion of the window frame, and requirements relating to sagging and application of excessive pressure on the door overall. Dynamic rigidity requirements arise from safety requirements during head-on and side-on crashes and from further requirements concerning passenger protection. Space requirements relate to practicable installation and operation of add-on and functional parts in or on the door; maintaining clearance spaces for installation work; maintaining minimum clearances to movable components; maintaining spaces between parallel areas, in particular for sealing purposes; separating the interior space of the door into dry areas and wet areas, etc.
In principle, the above-mentioned requirements for motor vehicle doors apply irrespective as to the particular design type of a motor vehicle door.
Up to now, steel sheet has been the most widely used raw material for motor vehicle doors. The conventional technique of a fully pressed door in shell technology is known. Such a door comprises two pressed shells which are interconnected and also connected to a glass channel frame. Later on, components are installed on the inner shell.
The frame door represents a further conventional door concept. The frame door comprises a window frame made from steel, said window frame comprising a rolled profile bent by stretching and rolling, which window frame is welded or screwed to a door box. The door box in turn comprises two pressed steel shells which are interconnected.
From the point of view of forming variants, a frame door comprising a window frame welded in the door box (modular system door) is advantageous. Such a steel door for motor vehicles is for example known from EP 0 476 351 A1. With this design type, some identical components can be used for different vehicle types.
It has been shown that the previously explained modular system door can also be produced from light metal/light metal alloys, in particular from aluminium alloys. A respective example, which represents the nearest state of the art, has been described in DE 196 16 788 A1. The lightweight door for motor vehicles described in the above mentioned patent specification comprises an outer skin of the door and a supporting frame, with the supporting frame comprising a hinge support forming one U-limb, a lock support forming the other U-limb, and a door bottom forming the U-stay. The hinge support and the lock support are cast parts made from a light metal alloy, in particular from an aluminium alloy, while the door bottom which connects them is an extruded profile, pressed profile or rolled profile made from a light metal alloy, in particular from an aluminium alloy. The supporting frame is closed off at the open top of the U by outer and inner window gutter profiles which can also be extruded aluminium profiles. Window channel profiles and hinge reinforcements complete the frame structure of this lightweight door. Designing the hinge support and the lock support as light metal cast parts makes it possible to achieve complex shapes, but is expensive.
In the above mentioned lightweight door which is known from the state of the art, the window frame which encompasses the window area and which is permanently connected to the door box, can be an extruded and bent light metal profile, in particular a light metal profile bent by stretching and rolling (see also DE 40 08 111 A1). This window frame which initially does not comprise any trim or moulding, will need to accommodate various add-on components. This includes seals as well as an inner roof rail panel which is attached using clips or clip-on fasteners (which require drill holes). This also includes a frame panel to be fitted externally, as well as a panel for the B-pillar.
The use of a multitude of add-on components on and around the window area of a vehicle door requires considerable installation effort. The various add-on components must be adjusted in relation to each other and carefully installed. Of course the tolerances of individual parts can add up, occasionally leading to unsightly large gaps.
It is thus the object of the invention, from the point of view of window frame design, to optimise the previously explained lightweight door for motor vehicles
The lightweight door for motor vehicles, according to the invention, meets the above-mentioned objective with the characteristics set forth herein. In this way, from the point of view of construction, the necessary add-on options on the window frame are provided.
According to the preferred embodiment of the invention, the light metal profile forming the window frame comprises at least one continuous acceptance groove and/or a continuous clip-on strip, so that add-on components can be accepted, fixed or attached at said location. For several add-on components, several such devices can be provided or it is possible to provide one such device for attachment or partial attachment of several add-on components.
Preferred embodiments and improvements of the basic teaching of the invention are provided as set forth herein.